This invention relates generally to a housing and mounting system for a strip lighting device, especially but not exclusively a lighting device of the kind in which multiple light emitting diode (LED) light sources are arranged at spaced intervals within an elongate housing that is translucent and arranged to diffuse, disperse or scatter the light from the LED light sources.
The present applicant""s international patent application PCT/AU98/00602 discloses a strip lighting device in which multiple LED light sources are arranged at intervals on a support strip within an extruded elongate housing. The housing is translucent and diffuses the light emitted by the LEDs, whereby the housing glows so as to form a strip or line of light. The housing has a base shaped to snap fasten onto complementary mounting rails that may be fastened along a wall or building feature. Although the essential concept has caused considerable interest, the form of housing disclosed and illustrated in our prior international patent application is limited in its applications because it is not easily formed into non-linear shapes and requires a backing flat surface for fixing the associated mounting rail. The housing is not well suited to highlighting complex architectural features or achieving other more complex shapes, and requires special connector pieces to go around building corners and the like.
Similar considerations apply to the housing disclosed in Japanese patent publication 09-258676. In that case, the elongated housing is formed in two parts, a base and a cover, and the light emitted by the LEDs (which stand up on the base) is dispersed or diffused by internally shaped surfaces.
The present applicant considered addressing the problem by utilising tubular housings of uniform circular cross-sections as a modification of its prior invention, which would apparently be possible given that the diffusion of the light is achieved by the body material of the housing rather than its internal or external profile. However, the preferred material for the housing is a polycarbonate plastic and it was found that attempts to extrude uniform tubes of this material result in an undesirable rotation of the moulding, unacceptable given that these are internal features of the tube such as for mounting the printed circuit board (PCB) strips on which the LEDs are supported.
It is therefore an object of the invention to achieve a housing for a strip lighting device which is more adaptable in its mounting than prior housings, and therefore broadens the range of applications of lighting devices of the above-discussed kind.
The invention entails a concept which simultaneously solves the difficulty discussed above in relation to extrusion of circular cross-section tubes in a translucent light diffusive material, and provides the means by which the housings may be mounted in a variety of applications. Specifically, the proposal of the invention is to form at least two longitudinally extending integral keys on the exterior of the tube.
The invention accordingly provides, in a first aspect, a housing for a strip lighting device, including:
an elongated tube which is preferably of substantially circular cross-section and is at least partially translucent; and
at least two longitudinally extending keys of substantially uniform cross-section on the exterior of said tube;
wherein said keyways are integrally formed with the tube, extend parallel to the axis of the tube, and preferably define an included angle between them at the axis less than 180xc2x0.
In a preferred embodiment, the keys are of round or rectangular cross-section, and said defined angle is preferably of the order of 120xc2x0, or at least between 90 and 150xc2x0. Advantageously, the keys are equi-angularly distant from a diametral plane parallel to the mounted position of a support strip for internal light sources, defined by formations on the interior of the tube.
In an advantageous arrangement, each key is radially or chordally aligned with a pair of ribs defining a groove to receive a support strip or other strip within the tube.
The key may be a rib or fin, groove or shoulder.
In a second aspect, the invention is directed to a strip lighting device which includes:
an elongate housing according to the first aspect of the invention;
a multiplicity of light sources arranged at intervals within the housing; and
means to diffuse, disperse or scatter light from said light sources whereby on activation of the light sources, a visible optical effect is produced when the housing is viewed from the outside.
Preferably, said effect is that the housing glows so as to form a strip or line of light.
Preferably, the means to diffuse, disperse or scatter light consists of or at least includes the housing itself.
Advantageously, the housing is a colour, e.g. a primary colour, such that the strip lighting device is visible as a housing of that colour when the light sources within are not activated, and is a glowing form of that colour when the light sources are activated.
In an advantageous application, said device may be shaped and/or connected together to form an illuminated display symbol or set of symbols, e.g. a numeral or letter of the alphabet, a larger number, word or script.
In a third aspect, the invention is directed to a support element for retaining and mounting a housing according to the first aspect for a strip lighting device according to the second aspect of the invention, which element includes a body, an opening through or recess in the body of a shape adapted to complement the elongated tube of said housing, and a pair of formations associated with said opening or recess to engage and locate the respective longitudinally extending keys of the housing of the first aspect of the invention.
In a preferred form of the support element, a projecting member has said recess at one of its ends, and said formations are on deflectable tips whereby said housing may be snap engaged with the support element by being pushed between said tips until said formations engage and locate the respective keys.
In a still further, fourth, aspect of the invention, there is provided a strip lighting system including:
a plurality of strip lighting devices according to the second aspect of the invention; and
a plurality of support elements according to the third aspect of the invention.
In this fourth aspect of the invention, there is also afforded a method of providing a building or other object with display or decorative illumination, including fitting the building or other object with plural strip lighting devices according to the second aspect of the invention by means of support elements according to the third aspect of the invention.